1. Field of the Invention
The present invention relates to a camera body having a body mount to which an interchangeable lens is detachably attached.
2. Description of the Related Art
A conventional camera body (e.g., an SLR camera body) utilizing an interchangeable lens is generally provided on the front face with a body mount (body mount ring) to which a lens mount (lens mount ring) fixed at the rear end of an interchangeable lens is detachably attached. The body mount and the lens mount together constitute a lens mount device (or simply called xe2x80x9clens mountxe2x80x9d) for coupling the lens to the camera body. Different types of lens mount devices are known. The most popular ones are the bayonet mount and the screw-type mount.
In a bayonet mount, when the lens is coupled to the camera body, firstly a body index mark on, or in the vicinity of, the body mount of the camera body and the corresponding index mark (lens index mark) on, or in the vicinity of, the lens mount of the lens are aligned, and then the lens mount is mounted onto the body mount. Subsequently, the lens is fully turned relative to the camera body in a predetermined rotational direction.
It is easy to attach the lens to the camera body while seeing the positions of the index marks under good light. However, in dim light or in the dark it is difficult to attach the lens to the camera body because the index marks cannot be clearly seen. Accordingly, formerly it is often necessary to carry a flashlight or an external light (which can be connected to a hot shoe on the camera body) together with the camera in case that the lens needs to be attached to the camera body in dim light or in the dark.
The primary object of the present invention is to provide a camera body having a device which makes it easy to attach the lens to the camera body even in dim light or in the dark.
To achieve the object mentioned above, according to an aspect of the present invention, a camera body is provided which includes a body mount adapted to detachably attach an interchangeable lens thereto, a body index mark which indicates a position of proper alignment of the interchangeable lens with respect to the body mount in order to attach the interchangeable lens to the camera body, and an illuminating device which illuminates the body index mark.
The body index mark is brought into alignment with a lens index mark of the interchangeable lens when the interchangeable lens is attached to the camera body.
Preferably, the body index mark includes a transparent member having a transparent projection fitted into a through hole formed on the body mount. The illuminating device includes a light source for lighting the transparent member from the inside of the camera body. Preferably, the transparent member is colored.
Preferably, the camera body further includes a lock mechanism for locking the interchangeable lens on the body mount after the interchangeable lens is properly coupled to the camera body, a lens-lock-release button which unlocks the lock mechanism when depressed, a switch which is open or closed in accordance with the operation of the lens-lock-release button, and a controller which turns the illuminating device ON or OFF in accordance with a change in an open/closed state of the switch.
Preferably, the controller turns the illuminating device ON at the time the open/closed state of the switch changes in accordance with a depression of the lens-lock-release button.
Preferably, the controller subsequently turns the illuminating device OFF after a predetermined period of time elapses.
Preferably, the camera body further includes a detector for detecting whether or not the interchangeable lens is attached to the body mount, wherein the controller controls the illuminating device such that the illuminating device remains OFF in the case where the detector detects that the lens mount is attached to the body mount even if the lens-lock-release button is depressed.
In an embodiment, the light source includes an LED positioned immediately behind the transparent member.
In an embodiment the camera body further includes a switch which can be manually turned ON and OFF, wherein the illuminating device includes a light source which is turned ON and OFF when the switch is turned ON and OFF, respectively.
In an embodiment, the body mount includes a bayonet type mount.
According to another aspect of the present invention, a camera body includes a body mount adopted to detachably attach an interchangeable lens thereto, a body index mark which indicates a position of proper alignment of the body mount with respect to the lens mount of the interchangeable lens when the interchangeable lens is attached to the camera body; an illuminating device which illuminates the body index mark, a detector adopted to detect whether or not the interchangeable lens is attached to the body mount, and a controller which prevents the illuminating device from turning ON when the detector detects that the lens mount is attached to the body mount.
According to another aspect of the present invention, a camera body includes a body mount adapted to detachably attach an interchangeable lens thereto, a lens-lock-release button which is manually depressed when the interchangeable lens is attached to the body mount, and a light source which is turned ON when the lens-lock-release button is depressed to attach the interchangeable lens to the body mount; the light source illuminating the body mount.
Preferably, a body index mark is further provided which is brought into alignment with a lens index mark of the interchangeable lens when the interchangeable lens is attached to the camera body; wherein the light source is turned ON to emit light towards the body index mark when the lens-lock-release button is depressed.
Preferably, the body index mark is made of a material which allows light to pass therethrough, the light source emitting light outwardly from inside the camera body via the body index mark.
The present disclosure relates to subject matter contained in Japanese Patent Application No.11-103843 (filed on Apr. 12, 1999) which is expressly incorporated herein by reference in its entirety.